Fleet is open source device management software. Prior to 4.81.0, Fleet contained multiple unauthenticated HTTP endpoints that read request bodies without enforcing a size limit. An unauthenticated attacker could exploit this behavior by sending large or repeated HTTP payloads, causing excessive memory allocation and resulting in a denial-of-service (DoS) condition. Version 4.81.0 patches the issue.

Affected: Go: github.com/fleetdm/fleet/v4

### Summary

Fleet contained multiple unauthenticated HTTP endpoints that read request bodies without enforcing a size limit. An unauthenticated attacker could exploit this behavior by sending large or repeated HTTP payloads, causing excessive memory allocation and resulting in a denial-of-service (DoS) condition.

### Impact

An unauthenticated attacker could cause the Fleet server process to exhaust available memory and restart by sending oversized or repeated HTTP requests to affected endpoints.

This vulnerability impacts **availability only**. There is:

- No exposure of sensitive data - No authentication bypass - No privilege escalation - No integrity impact

### Workarounds

If upgrading immediately is not possible, the following mitigations can reduce exposure:

- Apply request body size limits at a reverse proxy or load balancer (e.g., NGINX, Envoy). - Restrict network access to endpoints to known IP ranges where feasible. - Monitor memory usage and restart frequency for abnormal patterns.

### For More Information

If there are any questions or concerns about this advisory, please contact us at:

Email Fleet at [security@fleetdm.com](mailto:security@fleetdm.com)

### Credits

Fleet thanks @fuzzztf for responsibly reporting this issue.

Ein Angreifer kann mehrere Schwachstellen in Fleet ausnutzen, um einen SQL-Injection Angriff durchzuführen, um einen Denial of Service Angriff durchzuführen, um Sicherheitsvorkehrungen zu umgehen, um Informationen offenzulegen, und um beliebigen Programmcode mit Administratorrechten auszuführen.